According to the latest usage statistics posted on W3Techs dot com, over 90% of websites use JavaScript as a client-side programming language. At the same time, JavaScript, along with HTML5 and CSS3, is also being used widely by developers for building various cross-platform mobile apps and games. So it becomes essential for developers to know some of the fundamental aspects of JavaScript. Each developer also needs to understand the basic building blocks of JavaScript to use the dynamic programming language more efficiently.

Important Building Blocks of JavaScript

Data Types: JavaScript supports a lesser number of data types in comparison to other modern programming languages. But strings and numbers are integral part of JavaScript code. Broadly, JavaScript supports five data types, i.e., number, string, Boolean, null and undefined. String is a series of characters enclosed in either single (‘) or double quotes (“), whereas number can be either an integer or a floating-point number. At the same time, Boolean is a logical value which can be either true or false. Both null and undefined are special data types which can contain a single value. But null is represents no value or a value which is nothing, whereas undefined does not have any initial value.

String Literals: Normally, JavaScript string literals are used for storing and manipulating text. The string laterals can include normal characters as well as special characters. However, the programmers have to delimit the special characters using a backlash (\). For instance, to include a single quote, they have to write \’. Likewise, they have to write \” to include a double code. They also have option to use character code for horizontal tab, new line, and backlash, single quote and double quote, along with Unicode and Latin-1 characters. The value of string literals remains static or unchanged throughout the program run.

Variables: Like other programming languages, JavaScript also use variable as data items representing a specific memory storage location on the system. The programmers can assign only three types of data to the variables, i.e., string, numeric and Boolean. However, a JavaScript variable must have a name, value and type. Unlike literals, the value assigned to variables can change while the program is running. JavaScript does not require programmers to explicitly mention the data type of a variable. It can automatically identify the data type based on the type of data stored in the variable.

Arrays: The programmers also have option to use arrays in JavaScript to store multiple values in a single variable. For instance, they can store related values like apple, orange, grapes, pineapple and watermelon in a single array called fruits. The arrays are declared using the var keyword. But the programmers are required to store the values within square brackets. They can further refer to each elements of the array throughout the code. For instance, the members of fruit can be referred sequentially as fruit[0], fruit[1] and so on.

Functions: While writing JavaScript code, programmers can use functions to package and reuse certain functionality. They can include a block of code in a function, and execute the function to accomplish certain tasks. They can further the call the function each time the functionality is required and avoiding writing the code repeatedly. Normally, the name of a function looks similar to the name of variables. But functions in JavaScript are distinguished using brackets, i.e., (). Some built-in functions even allow programmers to write arguments within the brackets to accomplish specific tasks.

Objects: JavaScript treats each and everything as an object. It further allows programmers to store the object in a variable. For instance, the programmers can create a variable called “car” and add an object called “Fiat” to it. They can further assign different values to car like color, model, type and make. Likewise, they can perform certain actions on the objects by creating methods. The properties of an object can be accessed in two distinct ways. The programmers can write either objectName.propertyName (i.e., car.model) or objectName[“propertyName”] (i.e., car[“model”]. Likewise, the object method can be accessed by writing objectName.methodName().

Along with understanding the basic building blocks of JavaScript application development, the programmers also need to be familiar with popular JavaScript libraries and frameworks. These tools make it easier for programmers to create a wide range of applications by taking advantages of the features and functionality of JavaScript.